objective: there are few therapeutic options for treatment of multidrug resistant klebsiella pneumoniae isolates as a hospital infectious agent (nosocomial infection). the aim of this study was to evaluate the antibacterial activity of zataria multiflora boiss extracts against esbl-producing klebsiella pneumoniae strains. materials and methods: this study was conducted on 100 k. pneumoniae isola...

  Background and Objective: Organisms producing CTX-M β-lactamases are emerging as a source of resistance to oxyiminocefalosporins such as ceftriaxone and ceftazidime. However, the laboratory detection of these strains is not well defined. In this study, phenotypic assay for screening of extended-spectrum β-lactamases producing strains and molecular assay for the identification of CTX-M β-lact...

Resistance to extended-spectrum cephalosporins is often associated with plasmid encoded extended spectrum beta-lactamases (ESBL). In order to evaluate the prevalence and diversity of ESBLs in enterobacteria in our city, a 1-month-period survey was carried out from April to May 2000. Extended-spectrum-cephalosporin-resistant strains, isolated from inpatient clinical specimens other than stools, ...

BACKGROUND Despite increasing importance of Acinetobacter baumannii in nosocomial infections and rapid development of multi-antimicrobial resistance in this strain, the resistance mechanisms of beta-lactam antimicrobials in A. baumannii were not clearly defined. In order to observe the resistance mechanisms against beta-lactams and carbapenem, we characterized the production of beta-lactamases ...

By directed mutagenesis, we constructed a set of seven TEM-1 derivatives containing single replacements in each one of the amino acids substituted in naturally occurring extended-spectrum TEM beta-lactamases. The exact contribution of each mutation to the resistance phenotype was determined. In addition, mutant enzyme production and stabilities were studied. Five of seven mutations determined t...

conclusions the prevalence of esbl-producing klebsiella strains in shahid-beheshti hospital in kashan has increased. the study concluded that there was a high prevalence of the blactx-m type gene among esbl positive isolates. patients and methods one hundred klebsiella spp. were isolated from clinical specimens of hospitalized patients at shahid-beheshti hospital from december 2012 to november ...

From whole-cell DNA of a clinical isolate of the enterobacterial species Rahnella aquatilis, a beta-lactamase gene was cloned that encoded a chromosomally encoded Ambler class A enzyme, RAHN-1. RAHN-1, with a pI of 7.2, shares 76, 73, and 71% amino acid identity with the extended-spectrum beta-lactamase of chromosomal origin from Serratia fonticola and with the plasmid-mediated beta-lactamases ...

beta-Lactam resistance was studied in 1,072 consecutive P. mirabilis clinical strains isolated at the Clermont-Ferrand teaching hospital between April 1996 and March 1998. The frequency of amoxicillin resistance was 48.5%. Among the 520 amoxicillin-resistant isolates, three resistance phenotypes were detected: penicillinase (407 strains [78.3%]), extended-spectrum beta-lactamase (74 strains [14...